1. Field of the Invention
The present invention is related to dust boots for establishing contaminant blocking and lubricant retaining seal between a housing and a stud of a moveable joint.
2. Related Art
Dust boots made of rubber or other similar materials are often used on moveable ball socket joints to seal the socket by preventing contaminants from entering the socket and to prevent lubricants from escaping the socket. Such sockets typically include a housing and a stud which are pivotable relative to one through a wide range of motion. The dust boot must maintain seals with both the housing and the stud through the full range of motion of the housing and stud relative to one another. Often, metal or plastic rings are placed externally and around the outside circumference of the dust boot or are inserted within the dust boot adjacent opposite ends of the dust boot for biasing the dust boot against the stud and housing to establish the seals therebetween. The processes of manufacturing such types of moveable joints is often very labor intensive due to the large number of parts. Additionally, on occasion, the dust boot may be unintentionally torn during the manufacturing process, which leads to unnecessary waste and labor to replace the torn part. The use of external rings may also require the outer circumference of the housing to be machined so as to provide a surface configuration that is sufficient for capturing the dust boot and producing an acceptable seal.
Another option for establishing the seal between the dust boot and the housing is to capture an end of the dust boot under a crimped or spun edge of the housing. In this option, a metal or plastic ring may additionally be placed within the dust boot to restrict unintentional pull out of the dust boot from the crimp or spun edge during full articulation of the stud and housing relative to one another. However, this option may also have certain limitations. For example, the crimping or spinning process may fail to produce an adequate seal between the dust boot and the housing. Additionally, due to the mechanical properties of common dust boot materials, the dust boot may take a “compression set” after a certain amount of time and pressure, thereby weakening the seal between the dust boot and the housing. Overspinning or over crimping the housing onto the dust boot does not compensate for the possible “compression set” condition and may force some of the material of the dust boot to vacate the area between the mating surfaces.